Add a util to validate FILPoll votes

cmd/lotus-shed/main.go

@@ -53,6 +53,7 @@ func main() {
 		rpcCmd,
 		cidCmd,
 		blockmsgidCmd,
+		signaturesCmd,
 	}
 
 	app := &cli.App{

cmd/lotus-shed/signatures.go

@@ -0,0 +1,74 @@
+package main
+
+import (
+	"encoding/hex"
+	"fmt"
+	"strconv"
+
+	"github.com/filecoin-project/go-state-types/crypto"
+	"github.com/filecoin-project/lotus/lib/sigs"
+
+	"github.com/filecoin-project/go-address"
+	"github.com/urfave/cli/v2"
+	"golang.org/x/xerrors"
+)
+
+var signaturesCmd = &cli.Command{
+	Name:  "signatures",
+	Usage: "tools involving signatures",
+	Subcommands: []*cli.Command{
+		sigsVerifyVoteCmd,
+	},
+}
+
+var sigsVerifyVoteCmd = &cli.Command{
+	Name:        "verify-vote",
+	Description: "can be used to verify signed votes being submitted for FILPolls",
+	Usage:       "<FIPnumber> <signingAddress> <signature>",
+	Action: func(cctx *cli.Context) error {
+
+		if cctx.Args().Len() != 3 {
+			return xerrors.Errorf("usage: verify-vote <FIPnumber> <signingAddress> <signature>")
+		}
+
+		fip, err := strconv.ParseInt(cctx.Args().First(), 10, 64)
+		if err != nil {
+			return xerrors.Errorf("couldn't parse FIP number: %w", err)
+		}
+
+		addr, err := address.NewFromString(cctx.Args().Get(1))
+		if err != nil {
+			return xerrors.Errorf("couldn't parse signing address: %w", err)
+		}
+
+		sigBytes, err := hex.DecodeString(cctx.Args().Get(2))
+		if err != nil {
+			return xerrors.Errorf("couldn't parse sig: %w", err)
+		}
+
+		var sig crypto.Signature
+		if err := sig.UnmarshalBinary(sigBytes); err != nil {
+			return xerrors.Errorf("couldn't unmarshal sig: %w", err)
+		}
+
+		switch fip {
+		case 14:
+			approve := []byte("7 - Approve")
+
+			if sigs.Verify(&sig, addr, approve) == nil {
+				fmt.Println("valid vote for approving FIP-0014")
+				return nil
+			}
+
+			reject := []byte("7 - Reject")
+			if sigs.Verify(&sig, addr, reject) == nil {
+				fmt.Println("valid vote for rejecting FIP-0014")
+				return nil
+			}
+
+			return xerrors.Errorf("invalid vote for FIP-0014!")
+		default:
+			return xerrors.Errorf("unrecognized FIP number")
+		}
+	},
+}